Done. Moved to https://groups.google.com/forum/#!topic/ansible-devel/hLfmzlsxggM
On Thursday, July 3, 2014 1:02:43 PM UTC-7, Michael DeHaan wrote: > > This is more of a topic for ansible-devel, can you repost there? > > Thanks! > > > On Thu, Jul 3, 2014 at 3:10 PM, Stuart Reynolds <stuart....@gmail.com > <javascript:>> wrote: > >> I'm trying to understand what I can expect when writing my own modules. >> My hope would be to more quickly move and existing Makefile and shell >> script configuration to ansible. >> >> However, just testing a simple shell module: >> >> #!/bin/bash >> set -e # Not so useful -- return code is ignored by ansible. >> echo x=123 >> echo a=789 1>&2 # Output stderr >> echo y=456 >> exit 1 # Ignored by ansible :-( Succeeds if we get here. >> >> there's a lot I find confusing. >> >> (1) Here, only x and y are returned, not a, which seems to disagree with >> the documentation. From: >> http://docs.ansible.com/developing_modules.html#common-pitfalls >> >> Modules must not output anything on standard error, because the system >>> will merge standard out with standard error and prevent the JSON from >>> parsing. Capturing standard error and returning it as a variable in the >>> JSON on standard out is fine, and is, in fact, how the command module is >>> implemented. >> >> If a module returns stderr or otherwise fails to produce valid JSON, the >>> actual output will still be shown in Ansible, but the command will not >>> succeed. >> >> >> (i.e. stdout and stderr are NOT merged). In fact, if I comment out the >> lines to print x and y, ansible notes that there's no valid JSONy like >> output on stdout, reports a failure, which includes the values output to >> stderr. In fact if it looks like there's valid variables in stdout, it >> stderr is never examined (ansible succeeds even if there is garbage output >> on stderr, and the return code is ignored). Did I misread the docs? Or or >> the docs out of date? >> >> (2) The following... >> #!/bin/bash >> set -e # NB. RETURN CODE IGNORED BY ANSIBLE >> echo x=123 >> exit 1 # Simulate an error part way through my script >> echo y=123 >> succeeds! (as far as Ansible is concerned). Ansible always ignores the >> return codes (really?!) >> >> So, it seems that the only safe pattern when developing shell modules is: >> #!/bin/bash >> set -e # NB. RETURN CODE IGNORED BY ANSIBLE >> >> {do all your work here. Exit on failure. Return code doesn't matter} >> >> # Print result variables here on success. >> # Success must be guaranteed as soon as the first variable is output >> echo y=123 >> # failures here while printing other variables as treated as a success by >> Ansible! >> ./outputVars # Danger, danger! >> # Return code doesn't matter >> >> In other words... a lot of care is required when migrating shell modules >> in Ansible. >> A lot would be simpler if return code failures = ansible failures. >> >> (3) Debugging. How? The docs suggest that I'm not generally allowed to >> output stdout or stderr from my commands (only variables to be reported to >> ansible may be reported). So... I need to add >& /dev/null to every >> command? >> What's the best practice here for getting command failures reported to >> ansible? >> >> (4) >> #!/bin/bash >> set -e >> echo "x=123" 1>&2 >> gives: >> failed: [localhost] => {"failed": true, "parsed": false} >> invalid output was: x=123 >> >> Which looks to me to be valid output (its just on stderr). Is there any >> way for a module to return variables in the event of a failure? >> >> >> - Stu >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Ansible Project" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to ansible-proje...@googlegroups.com <javascript:>. >> To post to this group, send email to ansible...@googlegroups.com >> <javascript:>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/ansible-project/bf549223-3565-4c49-82f4-370b2e4c04f2%40googlegroups.com >> >> <https://groups.google.com/d/msgid/ansible-project/bf549223-3565-4c49-82f4-370b2e4c04f2%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> > > -- You received this message because you are subscribed to the Google Groups "Ansible Project" group. To unsubscribe from this group and stop receiving emails from it, send an email to ansible-project+unsubscr...@googlegroups.com. To post to this group, send email to ansible-project@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/ansible-project/2c568f82-87e1-4fae-b235-e14cdb7ab6cd%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
